A new report contains some disappointing news for former asbestos workers: The risk for mesothelioma does not go down when asbestos exposure stops.
A team of US and Italian researchers reached that conclusion after combing the medical literature for studies on the risk for mesothelioma.
Although the risk for several other cancers declines when the person is no longer in contact with the carcinogen, the study shows this does not apply to asbestos cancer.
Asbestos Increases Mesothelioma Risk
Asbestos is the primary cause of mesothelioma. It is a naturally-occurring mineral that is resistant to corrosion, does not burn, and makes an excellent insulator. Malignant mesothelioma was virtually unheard of until people started mining and using asbestos in industry.
Since then, the health risks among asbestos workers have become well-known.
Illnesses and deaths among workers forced many companies to stop using asbestos or to start using protective gear.
But a new study suggests that these protections were too little, too late for many. Even leaving the workplace may not help. The research shows that the risk for mesothelioma stays with a person long after exposure stops.
Measuring the Long-Term Impact of Asbestos Exposure
The new study involved a systematic review of the medical literature on the cessation of asbestos exposure and disease risk.
The researchers found nine relevant studies. Their analysis shows that the 10-year relative malignant mesothelioma risk after asbestos exposure was slightly higher than that of lung cancer.
“This analysis provides evidence that the risk of mesothelioma does not decrease after cessation of asbestos exposure, while lung cancer risk does,” conclude the researchers.
Why Does Risk for Mesothelioma Persist?
A big reason why the risk for mesothelioma persists after asbestos exposure stops is the character of asbestos fibers. Dust-sized asbestos particles are thin and sharp. They are just the right size to lodge deep in the tissue. Once inhaled or swallowed, asbestos fibers can stay in the body indefinitely.
Over time, inflammation, irritation, and released iron from these fibers may raise the risk for mesothelioma.
Mesothelioma symptoms may not appear until the disease is in an advanced stage. It is important for people who have been exposed to asbestos to make their doctor aware, monitor their health, and have regular checkups.
Boffetta, P, et al, “Risk of mesothelioma after cessation of asbestos exposure: a systematic review and meta-regression”, April 15, 2019, International Archives of Occupational and Environmental Health, Epub ahead of print, https://link.springer.com/article/10.1007%2Fs00420-019-01433-4